May 20, 1952 E. T. RIDGWAY FRAME CONSTRUCTION AROUND OPENINGS 0F TRAILER AND OTHER VEHICLES AND STRUCTURES Flled April 9. 1949 I N V EN TOR. Edmund. Ridgway EICTA A TTORNEY Patented May 20, 1 952 FRAMEICONSTRUCTION AROUND 'OP ENIN GS OF TRAILERSAND OTHERWEHICLES AND STRUCTURES Edmund; T; Ridgway, aklyn,- iN.l.L, .assignor (to The Budd C0mpany,-Philadelphia, Pa., a. corporation oflPennsylvania Application April9; 1949-; Serial No'.'-8'6,564-r 8 Claims.- (01. 296 -29) 1i. The-invention relates to the construction of certain partsof the framework surrounding-an opening in a =load supporting and stress trans= mitting wall, and 1 especially" to aside wall con struction of' Vehicle bodies such as trailer bodies; provided with' an opening v between :its-long-itudh nally-spaced supportingregionse' The main objectof the invention isthe elimination of "a 1 serious structural "weakness encountered an self-supporting'sheet 'metaI trai-lershaving-=a large load opening in one-breach side wall between the front andrear supports. Subordin'ate' objects of -the invention are the'achieve ment of themain 'objectwith aminimumof 'ex-- pense', labor, material and structural changes -in existing constructions-:
Thestructural "weakness-mo be =overcome by the invention consists therein that" trailers of" the above indicated type, in which the side walls aremainloadand stress transmitting 'elements, develop cracks at" the=lower corners -'of the side- Wa-IYopening: Such cracks'dangerously weaken the-=structure-so "-tha-tthey require immediate attention; and'they involve a-*major, expensive repair;
The invention overcomes the tendency to *de- Figure 2 is a fragmentary side elevation, on a larger scale; of theregion'of th'e trailer-sur-- rounded in Figure '1 by the dot-and-dash *line 2; Figure: 3 is'-- a fragmentaitrysection alon line 3 -3 01 Figure 2', on astill larger scale; and
Eigures4 and"5lareverticalisections along lines 4-'-4 and ii -5; respectively; of Figure -2 and on about the-same scaleas Figure 32 Thezi-illustratedltraile'r is"of'a well k-nown spot Weldedisheet: metal. construction in which floor; upright? Wa11s;?andi:IOOfiI arezmaintload support ing -z and:. stress: transmittingielements and; to gether; form: a sel i=supporting, generally prismatic' :body *to be: carried; without the :interposition'. of a" separate chassis frame,"in the front and-rear regions 1 at 8 and 9, respectively, bya tractor and by road wheels lnot shown).
Thesidewall il 0 -visibl'e in thes drawing; or each sidewall oiith'e body, is 'provided I with a loading opemn'gfis l l between theend supporting regions Bland :9zu The customary door for closing th'e f opening is not shown,v tom rail orv sill. member; I2 a rub rail I 3," Ion gitudinally, spaced .upright. posts of which only the postssls, |5, ;l6 ;.,ll and I8 atand nearrthe .l. opening. are. shown, longitudinally corrugated.
sheathing l9, anda headernor topchord. 20-. Sheathinglfiis structurally securedtoithe posts, the rubrail I3 and tothe header 29,. thetlatter connecting the side wall with the roof.)
Side rail l2 and-rub rail l3 are reinforced in and adjacent the region of the opening, III by an'angle-s'ection' rail 2!. and a Z-section rail 22 respectively. The reinforcing.means 2| and 22 extend'across and are structurally connected withthe' lower ends of the posts. I4 to 18, that is, with .the posts" flanking andnear' tothe opening, 1 I Rail 22 has itsdownwardly extend-. ing arm 23-over its "entire length structurally connectedby; a row 'of" welds 24 to" the bottom wall or'web' ZEanditsupWard-Iy extending arm ZB'by-a row ofwelds 2'! to the-upper flange'ZB of theinwardly'facingchannel-section rail I 3. Other spot weld connections between the parts described 'so fanare indicated-by small ms in the drawing 1 but require no" description because theymay be of customary-arrangement and have no direct=bearing on'=the featuresconstituting the invention;
The lower sill or 'chord structurecomprising the members l2; l3i 2 l and 22 'is furtherreinforced'inthe region of the do'oropeningyb'y an angle- Z'-. or double-angle section threshold member 29 whichby itsdownwardly extending flange-orrarm 30 overlaps-theinside ."of 5 arm. 26. In the customaryconstruction," this threshold member -29 is-:structurally secured over its:en-' tirei'length totthe arms '26 and" 28 by spot welds 3i; asshown in Figure 4;:
In accordance with the invention, the connectionbf member 29 -to the side-sill structureby the :welds -3l-is, however, restricted to-a'zone32, Figure-2,awhich is'spacedt atzbothendsa distance v'33 .from-.the=ends of. the member; 29. In the endregions=33, the member 29is :left without stress transmitting, connection and the weldsaZlconnect merely the-flanges: 26 and 28-, as illustratedinFigure 5.
Thealength of the regions: 33; which in regard to the member 29 may be called no-weld regions; depends on several factors, such-as the =width 'of the.- door opening, the magnitude of? the: stresses to ricetransmitted, 2 the strength :of' the :elements adjoinin'gc'thendoor: opening; and so 011. In: a trailer of the: otherwise conventional, illustrated constructionimade i of high. tensile: austenitic stainlesssseel, manufactured by-electricspotrweld; ing; having 2 a door opening :of about: 40'. width, effective? noaweldiregions 3310f about/ 3 A1. each were found :torgiverthe desiredsresult: However, thealengthuof the: regions or .zonesa3 3'limay be Side-wall I [I has a, bot-- varied as long as the desired reinforcing function of the member 29 is maintained while the connection of member 29 is effectively kept away from the corners of the opening.
The member 29 is preferably slightly shorter than the distance between the posts l6 and I! flanking the opening ll, so that a space of may be left at each end. It is important that member 29 is not, or at least not structurally, connected to the posts.
In assembling the illustrated construction, arm 23 of member 22 is connected throughout its length by the welds 21 to wall 25 of rub rail [3, and arm 26 is secured throughout the same length except for the region 32 to flange 28 by the welds 21. After this initial connection, member 29 is added and the welds 3| which extend through and connect all three flanges 2B, 28 and 39, as shown in Figure 4, are made in the region 32 while leaving flange 30 in the end regions 33 of the opening unattached.
The mere omission of the weld connections of the threshold member 29 in the regions 33 has the surprising result of avoiding the occurrence of cracks at the lower corners of the door opening. Such cracks, as mentioned hereinbefore, appear in the former constructions after a certain time period of use of the vehicle, such as after a year,
and involve a major, expensive repair of a trailer which, in the case of stainless steel construction, is supposed to last practically indefinitely. The long life expectancy, next to savings in dead weight, is an important factor enabling the use of such rather expensive material as stainless steel and the selling of bodies made thereof at a correspondingly high price. The purpose of using stainless steel in a vehicle body is, of course, largely defeated if after a relatively short length of time, be it one year, two years or somewhat more, as compared with the otherwise expected, very long life. of the structure, a, weakness manifests itself which leads to a breakdown or calls for an immediate major repair.
Extensive tryouts of the invention over a sufficiently long period of time give the assurance that the defect of the former construction is now actually and permanently overcome.
A tentative explanation of the great results achieved by merely omitting a, few weld connections is that the new construction avoids or at least minimizes stress concentrations which presumably lead to the cracks in the prior construction.
The new inventive principle is not restricted to the specific embodiment illustrated and described but is applicable to other structures where frame members extend from the outside or the inside to and end at a corner of an opening and where, consequently, the formation of cracks is encountered or expected. The invention is, for instance, applicable also to constructions using other connecting means, e. g., rivets, instead of spot welds.
What is claimed is:
1. In a vehicle body, a stress transmitting wall structure surrounding a multi-corner opening, an elongated member arranged in line with one of the margins and adjoining one of the corners of the opening, and structural connections between said wall structure and said member distributed over the length of the latter to the permanent exclusion of a substantial part of said length at and adjacent said corner, said part being, in case of a plurality of about equally spaced individual connections, several times the spacing between such connections.
2. In a vehicle body, a stress transmitting wall structure surrounding a four-sided opening, an elongated reinforcement arranged along one of the margins and between two of the corners of the opening, and a plurality of individual structural connections, such as spot welds, between said wall structure and its reinforcement distributed with about equal spacing over the greater part of the length of said reinforcement and margin but permanently left free of such connection along short parts of said length at and adjacent said corners, the length of said parts being at least several times the spacing between adjacent ones of said individual connections.
3. In a vehicle body having a stress transmitting wall surrounding an opening; having frame members extending along margins and structurally interconnected at corners of the opening, at least one of said members extending beyond said corners; and having a reinforcing member coextensive with a part of a frame member which extends beyond a corner, said reinforcing member ending near one of the corners of the opening and being connected with said firstnamed frame member over a large part of its length to the permanent exclusion of a region of several inches adjacent said one corner.
4. In a vehicle body of generally elongated prismatic configuration; a stress transmitting side wall provided with an opening between end supporting points of the body and with a lower chord structure; vertical posts, of which two flank said opening, structurally connected with said chord structure; a sheet metal shear panel structurally connected with said chord structure and said posts; a threshold member extending along the lower margin of said opening and being structurally connected with said chord structure over the greater part of the distance between but to the permanent exclusion of regions of substantial length adjoining the lower corners of the opening.
5. In a self-supporting body for highway freight vehicles: a stress transmitting side wall provided with a loading opening between end supporting regions of the body; a chord structure along the lower margin of and coextensive with said side wall, said structure comprising an upright web and a rub rail of inwardly facing channel-section along the upper margin of said web, said section having an upper and a lower marginal flange; upright, longitudinally spaced posts structurally connected to said web and said rub rail; a sheet metal shear panel structurally connected with said rub rail and said posts and constituting the panelling of the wall; longitudinally extending reinforcements extending through and in both directions beyond said door opening and being structurally connected with said web and rub rail and with the lower ends of some of said posts on both sides of said opening, said reinforcements ending short of the ends of the side wall; and a threshold member inserted between two of said posts which flank said opening, said threshold member being secured over the larger part of its length to the upper flange of said rub rail and its reinforcement but being free of such connections in regions at and adjacent the lower corners of the opening.
6. In a self-supporting body of generally elongated prismatic shape, a side wall comprising a lower chord structure, longitudinally spaced upright posts and a shear panel, all three structurally connected with each other, said chord structure and two of said posts defining the vertical sides and the lower side of an opening arranged between end supporting regions of. the body, a longitudinally arranged elongated reinforcing structure structurally connected with said chord structure in the region of the door opening and in regions extending longitudinally beyond said opening, said reinforcing structure ending short of the ends of said Wall; and a reinforcing threshold member inserted between the posts defining vertical sides of the opening and structurally connected throughout the greater part of its length to the upper margin of said chord structure and its reinforcement but left free of such connection in short regions adjacent such posts.
7. In a self-supporting body of generally elongated prismatic shape, a side wall comprising a lower chord structure, longitudinally spaced upright posts and a shear panel, all three structurally connected with each other, said chord structure and two of said posts defining the side and bottom margins of an opening arranged between end supporting regions of the body, elongated reinforcing means structurally extending along the lower margin of and longitudinally beyond said opening but ending short of the ends of said wall; said reinforcing means being connected throughout its length to said chord structure and on each side of said opening to at least two of said posts at and adjacent said opening; and a reinforcing threshold member inserted between the posts at the side margins of the opening and structurally connected throughout the greater part of its length to the upper margin of said chord structure and its reinforcing means 6 but left free of such connection in short regions adjacent said side margins.
8. In a vehicle body of generally elongated prismatic configuration, a stress transmitting side wall provided with an opening between supporting regions of the body, said side wall having a lower chord structure, vertical posts of which two flank said opening and a sheet metal shear panel structurally connected with said chord structure and said posts, said chord structure having an upright web along its upper margin, a threshhold member extending along the lower margin of the door opening and having an upright arm structurally overlappingly connected to said Web of said chord structure over the greater part of the lower margin of the door opening but to the exclusion of regions adjoining the lower corners of the opening.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,673,786 Warhus June 12, 1928 2,172,571 Theriault Sept. 12, 1939 2,382,584 Scheyer Aug. 14, 1945 2,495,782 Smith Jan. 31, 1950 OTHER REFERENCES Welding Instructions, Third edition, 1944, U. S. Maritime Commission.
Typhonite Eldorado, advertisement of Joseph Dixon Crucible Co. on page 129 of Engineering News-Record, October 26, 1939.